It's exciting for everyone when an actor's latest project, the de facto centrepiece of any celebrity profile, is as compelling as Mr Eric McCormack's new TNT summer drama Perception. Mr McCormack plays Dr Daniel Pierce, a neuroscience professor with paranoid schizophrenia who helps the FBI solve cases with his keen understanding of the human mind - and his intermittently useful hallucinations. Yes, it's another procedural, but one with engaging new ideas. And if the crisply rendered first few episodes are any indication, Perception already has impressive confidence about what it's setting out to do. The network's marketing department is certainly enjoying its promotional slug, "Crime scene differently".

Meanwhile, the married Toronto native, and father of nine-year-old son Finnigan, graciously manages the worthwhile headache of being so closely associated with Will Truman, the gay, comedic straight man he embodied from 1998 to 2006 on the ground-breaking sitcom Will & Grace (winning the Emmy for Lead Actor in a Comedy Series in 2001). With Perception, he is well positioned to join the club of television stars known for two signature roles that includes Mr Bryan Cranston (Malcolm in the Middle, Breaking Bad) and Mr Michael C Hall (Six Feet Under, Dexter). "You'll never ever hear me complaining about being Will Truman. But it does create a real challenge any time something enters the zeitgeist that way," Mr McCormack says. "I did a show a couple of years ago with Tom Cavanagh called Trust Me that I really loved but it didn't last more than 13 episodes. But you try things and see what sticks. And I think this one is significantly different from Will."

I loved the idea of a guy who was so brilliant about everything the brain is capable of but is also at the mercy of it

What's nice about Perception is that it doesn't feel like a forced separation. Dr Pierce's strategically mussed hair is a curiously effective distinction, as is the autumnal New England wardrobe that makes you realise how radically slim fit Will Truman actually was. In explaining Pierce's costuming, Mr McCormack offers the best argument in favour of Americana "heritage looks" since anchors first slinked across placement print tees - that they're a buffer against schizophrenia. "I learnt that as soon as they have their first break with reality, in high school or early college, a lot of things freeze for them," says Mr McCormack, who is a John Varvatos devotee in his civilian life. "It's very common to stick with things that they know, even 20 or 30 years later. He needs the comforts of home, he needs the routine."

But if Mr McCormack has consistently demonstrated a taste for far-flung roles - from the 2008 television science fiction mini-series The Andromeda Strain, to the early career distinction of playing Mses Mary-Kate and Ashley Olsen's father in the 1993 television movie Double, Double, Toil and Trouble - he was not seeking a crime show. "It's not really my genre," he says with charming wryness. But Mr McCormack could see Perception's potential (he is also a producer on the show). Among its distinctions is its open discussion of brilliance and madness, a conversation that has been tiptoeing into the popular consciousness with the fetishisation of "gifts" in recent entertainments such as Touch and Extremely Loud and Incredibly Close. What is a gift and what should be medicated? "I loved the idea of a guy who was so brilliant about everything the brain is capable of but is also at the mercy of it," he says of Pierce, who avoids prescriptions, often to his detriment. "He totally walks that line." It's bold storytelling that comes with familiar accountability. "When we started Will & Grace in 1998 there was trepidation, a sense that we had a responsibility to the gay community to do this properly without pandering," Mr McCormack says. "It's kind of the same here. We can not use schizophrenia as some kind of a gimmick."